Coordination between stochastic and deterministic specification in the Drosophila visual system.
Maximilien CourgeonClaude DesplanPublished in: Science (New York, N.Y.) (2019)
Sensory systems use stochastic fate specification to increase their repertoire of neuronal types. How these stochastic decisions are coordinated with the development of their targets is unknown. In the Drosophila retina, two subtypes of ultraviolet-sensitive R7 photoreceptors are stochastically specified. In contrast, their targets in the brain are specified through a deterministic program. We identified subtypes of the main target of R7, the Dm8 neurons, each specific to the different subtypes of R7s. Dm8 subtypes are produced in excess by distinct neuronal progenitors, independently from R7. After matching with their cognate R7, supernumerary Dm8s are eliminated by apoptosis. Two interacting cell adhesion molecules, Dpr11 and DIPγ, are essential for the matching of one of the synaptic pairs. These mechanisms allow the qualitative and quantitative matching of R7 and Dm8 and thereby permit the stochastic choice made in R7 to propagate to the brain.
Keyphrases
- cell adhesion
- cerebral ischemia
- resting state
- white matter
- oxidative stress
- cell death
- endoplasmic reticulum stress
- systematic review
- spinal cord
- magnetic resonance imaging
- subarachnoid hemorrhage
- multiple sclerosis
- type diabetes
- mass spectrometry
- computed tomography
- heat shock
- decision making
- signaling pathway
- weight loss
- heat stress
- prefrontal cortex